| Wendell,
Large electric motors have a couple of parameters that protect them. The first is instant overloads. These prevent these motors from exceeding a predetermined amperage( thus HP). If a motor is said to be able to operate at 100 amps then typically the motor instant overload is set for 200 amps. This allows a motor to RELIABLY start. If IO is exceeded it will shut down the motor, preventing the good things inside the motor from coming apart. The second is thermal overloads. This is usually set around 1.3 times the rated amps. The TO allows you to exceed the amp rating for a period of time until the thermal capacity of the motor is in danger.
Bill Dube is probably not using either of these to protect the motor on his bike so he can generate more power but is sacrificing his RELIABILITY. He is only running the motor for a few seconds so it is much less important than the use in a plane for example. If you can determine the continuos HP needed for you to fly at altitude. Then get there before your engine overloads it's thermal capacity, you can reliably operate at that HP rating. Hope this helps! Cause HP is HP.
Bob On Jul 8, 2006, at 11:58 AM, Ed Anderson wrote: I would hazard a guess that Wendell is probably alluding to the better energy conversion efficiency of an electric motor over an internal combustion engine. Assuming the same energy input (whether in the from of electricity or gasoline) a typical electric motor is around 50% efficient where as the piston engine is around 25% efficient in converting input energy to mechanical energy. So for the same energy input an electric motor should give better conversion efficiency. So you might get 100 HP out of a motor for a 200HP (electrical energy) input - whereas to get 100 HP out of a piston engine you would need 400 HP of energy input (in the form of gasoline) - the rest being "wasted" in form of exhaust and cooling energy (and some friction). However, I agree with Jarret 1 HP = 1 HP regardless. Ed
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